Lubricating oils



Patented Jan. 4, 1938 UNITED STATES PATENT OFFICE LUBRIGATING OILS the -Main, Germany No Drawing. Application March 28, 1935, Serial 4 Claims.

The present invention relates to improved lubricating oils, especially such as are improved with regard to their colour or bloom.

We have found that lubricating oils can be improved in various respects by adding thereto, preferably in small amounts, an oil-soluble vacuum residue, which is solid at ordinary temperature and which is derived from de-asphalted hydrocarbon products containing cyclic, i. e., aromatic and/or naphthenic constituents, by which term are comprised tars, asphalt-basic or mixed basic mineral oils, especially from thehydrogenation products of the same, or from destructive hydrogenation products of coals or coal tars, pref erably mineral coals or mineral coal high temperature tars. By reason of the said addition the setting point and the turbidity point of the lubricating oils is lowered and. a good greenish fluorescence or bloom is imparted to the oils. Moreover, the formation of foam from the oil in motors is prevented. g

In order to prepare the said additional agents, the initial material for the preparation of the vacuum residue is treated with flocculants, as for example benzine rich in hydrogen, gas oil or liquefied normally gaseous hydrocarbons, whereby the asphalts are precipitated. The deposited substances are separated and the oil is subjected to a vacuum distillation. The latter is preferably carried out up to a temperature of from 300 to 350 C. under apressure of from '7 to 8 millimeters (mercury gauge). In this manner a product which is solid but readily soluble in lubricating oils is obtained; an addition of from0.05 to 3 per cent produces the effect already described.

The following example will further illustrate how this invention may be carried out in practice but the invention is not restricted to this example.

Example There are added to a destructive hydrogenation product, boiling above 350 0., of mineralmineral coal.

In Germany March 29, 1934 times its amount of a light benzine with which has been incorporated 10 per cent of petroleum ether, while stirring. After allowing to stand for several hours, the asphalt is precipitated and is then removed by filtration. Distillation is then efiected until only one third of the precipitant added remains. The mixture is then refined with per cent sulphuric acid and then with 20 per cent caustic soda solution, washed with water and dried. The oil is freed from the hydrocarbons of low boiling point which have been added by distillation and then distilled up to 350 C. under a pressure of 8 millimeters (mercury gauge). The residue remaining is a red-brown resin. If this be added in an amount of 0.2 per cent to a lubricating oil of bad color, an oil having a good green fluorescence is obtained. Moreover,,the setting point and turbidity point are lowered.

What we claim is:

1. A lubricant comprising a major proportion of a lubricating oil and a minor proportion of a residue which is solid at ordinary room temperature and which is derived by vacuum distillation from a deasphalted destructive hydrogenation product of a coaly material.

2. A lubricant comprising a lubricating oil and between 0.05 and 3 per cent of a residue which is solid at ordinary room temperature and which is derived by vacuum distillation from a deasphalted destructive hydrogenation product of a coaly material.

3. A lubricant comprising a major proportion of a lubricating oil and a minor proportion of a residue which is solid at ordinary room tempera ture and which is derived by vacuum distillation from a deasphalted destructive hydrogenation product of mineral coal.

4. A lubricant comprising a lubricating oil and between 0.05 and 3 per cent of a residue which is solid at ordinary room temperature and which is derived by vacuum distillation from a deasphalted destructive hydrogenation product of MATHIAS PIER. WILLY HIRSCHBERGER. HEINZ LEMME. 

